Sanyo Electric Co., Ltd.

Junichi Yogo

Keisuke Minami

Masashi Muraoka

A nonaqueous electrolyte secondary battery according to an embodiment of the present disclosure includes a separator which contains a first region located in a flat part of an electrode body and second regions located in a pair of curved parts, the ratio (B/A) of the air permeability (B) in each of the second regions to the air permeability (A) in the first region being 0.5 or more and 0.9 or less. Further, in a section passing through the center in the axial direction of the electrode body and being perpendicular to the axial direction, the ratio (SB/SA) of the sectional area (SB) of the pair of curved parts to the sectional area (SA) of the flat part is 0.28 or more and 0.32 or less.

Nonaqueous electrolyte secondary battery

A nonaqueous electrolyte secondary battery according to an embodiment of the present disclosure includes a negative electrode mixture layer which contains a first region located in a flat part of an electrode body and second regions located in a pair of curved parts of the electrode body, the ratio (B/A) of the packing density (B) in each of the second regions to the packing density (A) in the first region being 0.75 or more and 0.95 or less. Further, in a section passing through the center in the axial direction of the electrode body and being perpendicular to the axial direction, the ratio (SB/SA) of the sectional area (SB) of the pair of curved parts to the sectional area (SA) of the flat part is 0.28 or more and 0.32 or less.

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Hyogo, Japan

Junichi Yogo